ELECTROCARDIOGRAPHIC CHANGES MITRAL COMMISSUROTOMY
HARRY GROSS, M.D., EDITH R. KEPES, M.D., DENNISON AND CIIARLES D. ENSELBERG, M.D. NEW YORK,
ESPITE the great number of surgical operations performed in the past few years for the relief of mitral stenosis there is a surprising paucity of published observations on the electrocardiographic changes associated with the procedure. We are aware of only two publications dealing primarily with this subject, one based upon twenty-four,’ the other upon sixty cases.” The present report summarizes experience with the first 100 patients subjected to mitral comInissurotomy at Montefiore Hospital. The operations were performed by the surgical members of the cardiovascular team. This experience includes the frequent use of antiarrhythmic and antihypotensive drugs. It has been our practice to perform cardiac surgery under continuous electrocardiographic monitoring by a member of a cardiovascular team. The purposes of this paper are to describe the behavior of the heart during operation, to evaluate the use of the previously mentioned drugs, and to assess the value of electrocardiographic monitoring during operation. MATERIAL
The patients were carefully selected for surgery on the basis of disability attributable to pure or predominant mitral stenosis. According to Harken’s” classification there were twenty in Class II, fifty-seven in Class III, and twentythree in Class IV. All but four who were operated upon early in the series were fully digitalized at the time of operation and were deemed to be in an optimal state of compensation commensurate with their disease. The youngest patient was 19 years of age, and the oldest, 58. Ten were over 50 years old. Preoperatively normal sinus rhythm was present in forty-three and atria1 fibrillation in fifty-seven patients. Continuous monitoring was carried out by observation of the image on a Sanborn Cardioscope or a Cathode-ray oscilloscope.* When graphic records were desired, the circuit was switched to a Sanborn Visa-Cardiette. Continuous oximetric determinations were recorded on a Waters-Conley oximeter. _--From thr Medical Division arid D~partmwt, of Aw?sthesiology, MonteAore Hospital, New York, N.Y. Received for publication Jan. 8, 1955. *Part of a multiple-channel recording device specially built by Electronics for Medicine, Inc., New York. N.Y. 373
Patients were premeditated with morphine or morphine and secobarbital sodium. Atropine was also given in the earlier group of patients, but was later discontinued because of the occasional development of tachycardia preoperativelq-. Induction of anesthesia was accomplished with Thiopental sodium or secobarbital sodium and maintenance was carried out with 50 per cent nitrous oxide and 50 per cent oxygen with ether. Intubation was accomplished with topical five per cent cocaine in 60 patients, nitrous oxide and ether in twent>.four, cyclopropane in eleven, and a muscle relaxant was added in five (tlTubocurarine or Flaxedil). RESI-I,TS
Electrocardiographic changes were found in all the patients at various times during the procedure. In addition to arrhl-thmias these included variations in amplitude and form of atria1 and ventricular deflections, depression of RS-T segments, changes in form of 1‘ waves, and minor alterations in rate. No constant relationship of RS-T segment depression to arterial oxygen saturation or blood pressure level was found. The most striking and most cotnmon change was the appearance of arrhythmias at one or more stages of the operation (Table I). In general the frequency and severity of arrhythmias increased in the later stages when physical manipulation of the heart and the actclal commissurotomy were being done. During induction and intubation the arrhythmias were generally benign, consisting of minor alterations of rate due to disturbances of the S-A4 or ,4-V node or to occasional ventricular premature s)-stoles. ‘TABLE
Sinus tachycardia Sinus bradycardia A-V block Nodal rhythm and interference dissociation Atria1 premature systoles Nodal premature systoles Supraventricular tachycardia Atrial flutter and fibrillation Ventricular premature systoles Ventricular tachycardia Ventricular flutter and fibrillation
NO. OF PATIENTS
MANIPITI.ATION 01 HEAR’1 AND PIIRI-
I ~ COMMISSUROTOMk
’ ’ 2 9 1
1 2 1
1 I.1 3
1 6 4;: 17 2
Ventricular premature systoles of increasing frequency and ventricular tachycardia were the commonest irregularities and were definitely associated with mechanical stimulation of the heart and stretching or occlusion of the mitral orifice. Often they subsided almost immediately after the mechanical stimulation ended without the use of cardiac drugs. There were five operative
Fig. l.-All by interferwvx and lower nodal
strips are Lead II. Normal sinus dissociation (st,rips 2 and 3), lower rhythm (strips 5 and 6).
.4-V conduct,ion interference
Fig. 3.- -Five examples of “irregular mitral orifice or the act of commissurotomy. are Lead II.
ventricular tachycardia” The first two strips
associated with obstructior, of the are of the same patienl. All slIrips
Manipulation of the pericardium. Sinus tachycardia (strip 1) Fig. 4.-All strips are Lead II. followed by atria1 tachycardia with varying A-V block (strip 21, ventricular premature systoles and restoration of normal sinus rhythm on cessation of manipulation (strio 31.
deaths, the terminal rhythms being ventricular fibrillation in three, idioventricular rhythm and arrest in one, and ventricular tachycardia and arrest in one. Four mortalities occurred in Class IV patients and one in a (‘lass III Ijatient. Specific cardiac treatment was undertaken only when m arrhythmia was unduly prolonged or when a protracted fall in blood pressure occurred. Twentyeight patients were so treated (Tables II and III). In some instances several drugs were given concomitantly. About three-fourths of the patients received no tlrugs other than the anesthetic agents. II.
~ NO. OF PATIENTS
13 Good 4 Poor 1 Died
2 Hypotension hemorrhage Methosamine (Vasosyl)
1 Ventricular bigeminy 2 Ectopic beats with increased ventricular rate
NO. OF PATIENTS __--
Procaine amide (Pronestyl)
Supraventricular tachycardia Atria1 tachycardia Supraventricular bigeminy Irregular ventricular tachycardia Ventricular bigeminy
~ 3 Atrial fibrillation with rapid ventricular rate 1 Supraventricular tachycardia
Quinidine ___~-_~~Sodium thiobarbiturate (Pentothal) --------~ Neostigmine (Prostigmine)
I 3 __~~-_ 2
Sinus tachvcardia Supraventricular
Died 0” 0 Good 0 (
0 2 Good
0 Good 0 Good
It is worthwhile to review the changes during the various stages of operation. During induction important arrhythmias rarely occurred. In intubation the changes observed were of the same ty.pe as in induction but occurred more frequently. The arrhythmias developing during intubation have been attributed to vagovagal reflexes,” depth of anesthesia, anoxia, and carbon dioxide excess among other causes. In the hands of a skilled anesthetist arrhythmias lessened when “bucking” on the tube with its resulting hypoxia, and respiratory acidosis was prevented.” One patient developed an idioventricular rhythm during intubation, then a ventricular arrhythmia that could not be controlled and ended fatally. This was one of the two rare anesthetic deaths. Obviously there is danger of serious arrhythmias during intubation especially in patients with advanced underlying heart disease. Maintenance of anesthesia did not offer a problem. Difficulty arose only when instrumentation or manipulation of the pericardium, myocardium, or valve caused a fall in blood pressure, arrhythmia, or both. Tachycardia was often associated with a fall in blood pressure especially when chronic anoxia was present due to advanced heart disease. This situation, if it persists, requires treatment since patients with tight mitral stenosis do not long tolerate a fall in blood pressure. Reduced cardiac output or increased left atria1 pressure oft,en develops. The former may cause shock; the latter, pulmonary edema. In such instances it is of the utmost importance to complete the operation before irreversible changes occur. In our experience the most important arrhythmias occurred in association with insertion of the finger into the mitral orifice and during actual performance of the commissurotomy. Bursts of premature systoles and paroxysmal tachycardias, usually of ventricular origin, occurred in almost all cases. This has been noted by others.i,’ Such changes are not difficult to understand as there is not only mechanical stimulation of highly sensitive cardiac tissue, but also marked anoxia resulting from complete cessation of the circulation when the finger is in the mitral orifice. The serious ventricular arrhythmias and hypotension contingent upon this procedure usually disappeared upon removal of the finger or completion of the commissurotomy. In forty--four of our patients ventricular tachycardra developed during operation. The paroxysms varied in duration from a few seconds to several minutes, were sometimes intermittent and sometimes continuous, and occasionally of multifocal origin. Twenty-two of these cases were not treated, and the operations were successfully completed without the use of drugs. Only those cases were treated in which the paroxysms were prolonged or were accompanied by- distinct hypotension (Tables II and III). It follows that even in ventricular tachycardia with hypotension resulting from manipulation, there is no cause for concern, providing that this phase of the operation is completed quickly, before changes develop that perpetuate arrhythmia and hypotension.
In many instances the ventricular tachycardia was markedly irregular. This arrhythmia appeared in patients with normal sinus rhythm as well as in Also it was often preceded and followed by isolated those with atria1 fibrillation. ventricular premature systoles of similar form to the ventricular deflections during the tachycardia. Therefore, we designated the arrhythmia as “irregular ventricular tachycardia.” Campbell and Reynolds2 have also been impressed by this type of ventricular tachycardia. Among the rarely observed changes were some surprising alterations of rhythm. In one case atria1 fibrillation reverted to normal sinus rhythm, and in two, atria1 fibrillation changed to flutter. However, these were all transient and were succeeded by atria1 fibrillation within a few minutes. These changes occurred without the influence of drugs, and we are unable to explain them. A 1 per cent procaine solution in the pericardium has been said to abolish ventricular ectopic beats and to decrease myocardial irritability upon manipuIn our first 100 patients one or more drugs were administered in twentylation.6 eight. On the whole the results were disappointing. Restoration of the basic Most rhythm with intravenous procaine amide was rarely accomplished. successful was the use of norepinephrine in combating a fall in blood pressure, but in three patients the drug increased the ventricular arrhythmia and in another it induced this arrhythmia. In tachycardia of supraventricular origin and in atria1 fibrillation Spiegel and associates’ used neostigmine in fifteen of twentyThough we four reported cases and were favorably impressed with its action. have had little experience with it, we feel the drug appears deserving of use, Many patients can be managed without drugs. As experience progressed this became more apparent, so that of the 100 cases almost three-fourths received no drugs other than the anesthetic agents. In patients with heart disease it was natural for us to seek relationships between anoxia manifested by fall in oximeter readings, and blood pressure levels and RS-T depression. No such links were found. There was, however, the well-established relationship between tachy-cardia and RS-T depression, independent of anesthesia or surgical technique. There appeared to be no correlation between the age or clinical condition of the patients and the development of arrhythmias of various tyvpes. Kor can the influence of digitalization upon the development of arrhythmias be estimated since practically all the patients in this series were fully digitalized at the time of operation. THE
Electrocardiographic observation during major surgery and especially during commissurotomy is of distinct value. Changes in rate and rhythm during cardiac surgery can often be detected only- by the electrocardiograph. It is an established fact that such changes are frequently missed by the clinician or anesthesiologist. In so simple a matter as the rate of the heart a fairly large proportion of the beats may be missed by the palpating finger. Ziegler’ reports that of 80 per cent of arrhythmias revealed by- the electrocardiograph, only 6.5 per cent were recognized by ordinary means.
Fortunately in most cases this loss of accuracy is not important in the clinical course and need cause no concern, but because it is not possible to foretell which minor arrhythmia will lead to a serious one and because similar electrocardiographic changes may occur in every phase of operation, continuous knowledge of the electrical activity of the heart is important. An arrhythmia, whether supraventricular or ventricular, if it lasts long enough may’ result in a dangerous fall in blood pressure, progressive anoxia and shock with possible fatal termination. Most probably it is not the arrhythmia per se, but the shock consequent to the arrhythmia which is of the greatest importance. This, of course, will be recognized by the anesthesiologist and treated irrespective of the electrocardiographic inscription at that time. Rasically, it is of little significance whether at such a time the arrhythmia is ventricular or supraventricular in 01 igin. In fact, frequently the experienced cardiologist is unable to tell this either at the time of inscription or later with many hours to ponder over the record. Thus, since the anesthesiologist can watch the blood pressure and the rate and rhythm of the heart and cope with shock, it appears to us that most cases could easily be managed without a cardiologist. The surgeon can handle cardiac arrest and ventricular fibrillation. The place of the cardiologist is chiefly, in the selection of patients for operation and in the preoperative and postoperative management of arrhythmias, congestive failure, and carditis.
Continuous electrocardiographic observations were made on 100 paundergoing mitral commissurotomy. 2. Changes occurred in every case and included practically every known abnormality of rate and rhythm, as well as variations in form and amplitude of atria1 and ventricular defections. 3. The most frequently encountered serious arrhythmia was ventricular tachycardia (44 cases), usually irregular and associated with occlusion of the mitral orifice by the surgeon’s finger. 4. In three-fourths of the cases it was unnecessary to use any drugs. Indeed, only one-half the cases of ventricular tachycardia were treated. The best response to drug therapy resulted from the use of vasopressor agents. 5. No constant causal relationship was found between blood pressure or oximetric determinations and RS-T deviations. tients
1. Most of the arrhythmias appearing during mitral commissurotomy are surprisingly benign and rarely require heroic pharmacologic measures. 2. The prevention of shock is probably more important than the control of arrhythmias. 3. Continuous electrocardiographic monitoring is very helpful, but it is not necessary for a cardiologist to be present at every operation.
Es presentate un revista de1 experientias in 100 cornmissurotomias executate pro stenosis mitral. 11 es interessante notar que arrhythmias, ben que frequente, esseva usualmente benigne, excepte durante manipulation de1 corde e durante le obstruction de1 orificio mitral per le digit0 de1 chirurgo. Iste arrhythmias cessava in le majoritate de1 cases quando le manipulation de1 corde habeva ressate o quando le commissurotomia esseva completate. Drogas vasopressor csseva de adjuta in hypotension e associate arrhythmias. Kos opina que le contribution principal de1 cardiologo non consiste in le surveliantia electrocardiographic de1 operation mesme sed plus tosto in le selection de1 patientes con bon prognoses chirurgic e in lor observation pre- e postoperative.
1. 2. 3. 4. I5 . 6. 7.
R. J., Long, J. B., and Dexter, L.: Clinical Observations in Patients Undergoing Finger Fracture Mitral Valvuloplasty. II. Electrocardiographic Observations, Am. J. Med. 6:631, 1952. Campbell, M., and Reynolds, G.: Electrocardiographic Changes During Operations for Mitral Stenosis, Cardiologia 21:642, 1952. Harken, D. E., Ellis, L. B:, Dexter, L., Farrand, R. E., and Dickson, J. F.: The Responsibility of the Physician in the Selection of Patients With Mitral Stenosis for Surgical Treatment, Circulation .5:349, 1952. Reid, L. C., and Brace, D. E.: Irritation of the Respiratory Tract and Its Reflex Effect Upon the Heart, Surg., Gynec. & Obst. 70:157, 1940. Kepes, E. R., Margolius, B. R., and Nagel, S.: Anesthetic Problems in Mitral Commissurotomy. Presented at the 148th Annual Convention of the Medical Society of the State of New York, May, 1954. Beck, C. S., and Mautz, F. K.: The Control of the Heart Beat by the Surgeon With Special Reference to Ventricular Fibrillation, Ann. Int. Med. 106:525, 1937. Ziegler, R. F.: The Cardiac Mechanism During Anesthesia and Operation in Patients With Congenital Heart Disease and Cyanosis, Bull. Johns Hopkins Hosp. 83:237, 1948.